Vehicles utilize a number of fluid systems to operate components. A significant vehicular fluid system is a hydraulic brake system in which force applied to a brake pedal is amplified and transmitted to brake drums or disks via a hydraulic system. Therefore, the present invention will be discussed in the context of a hydraulic automotive brake system but is not so limited. Other automotive fluid systems include, for example, power steering, oil, and automatic transmission systems.
The basic functions performed by a system for removing and replacing vehicle hydraulic fluid include removing old hydraulic fluid from a master cylinder, vacuuming out old fluid through bleeder valves, refilling the brake fluid lines and master cylinder while keeping moisture and other contaminants from entering the new fluid and keeping air out of the brake fluid lines. The old fluid must be delivered to a suitable waste container. Such functions have been performed by prior art system.
Prior systems, however, do not address considerations that have become more significant in view of the increasing sophistication of brake fluid and brake systems, federal regulations, and quality assurance. It is desirable to have a hydraulic fluid changing apparatus that can require that input information is provided to assure that the container of brake fluid being utilized is appropriate for use. It is desirable to assure that the container from which the brake fluid is drawn has not been refilled and reused. This can prevent the use of counterfeit, contaminated, or inappropriate products. The United States Department of Transportation has established grades such as DOT 3, DOT 4, DOT 5, and DOT 5.1. Each has a different formula and characteristics. DOT 3 fluid is the least expensive grade, most widely available and most widely used. DOT 4 fluid is more expensive. DOT 4 fluid has a higher boiling point making it more suitable for high-performance applications such as Automatic Brake Systems (ABS). Capacity to recognize that the appropriate fluid is being used in a particular car is a desirable capability.
While prior systems have accounted for proper disposal of used brake fluid, disposal of remaining new, clean brake fluid has not been addressed. However, clean brake fluid is a hazardous material in terms of disposal regulations just as well as used brake fluid. It is further desirable to provide a system that communicates many different conditions to a service technician to maximize ease of use of the apparatus and minimize improper handling of new or used hydraulic fluid.